Remove Python 3.5 builds from .appveyor.yml

Numpy no longer supports Python 3.5.

Author: charris

.appveyor.yml

@@ -26,14 +26,6 @@ environment:
       DAILY_COMMIT: master
 
   matrix:
-    - PYTHON: C:\Python37
-      PYTHON_VERSION: 3.7
-      PYTHON_ARCH: 32
-
-    - PYTHON: C:\Python37-x64
-      PYTHON_VERSION: 3.7
-      PYTHON_ARCH: 64
-
     - PYTHON: C:\Python36
       PYTHON_VERSION: 3.6
       PYTHON_ARCH: 32
@@ -42,12 +34,12 @@ environment:
       PYTHON_VERSION: 3.6
       PYTHON_ARCH: 64
 
-    - PYTHON: C:\Python35
-      PYTHON_VERSION: 3.5
+    - PYTHON: C:\Python37
+      PYTHON_VERSION: 3.7
       PYTHON_ARCH: 32
 
-    - PYTHON: C:\Python35-x64
-      PYTHON_VERSION: 3.5
+    - PYTHON: C:\Python37-x64
+      PYTHON_VERSION: 3.7
       PYTHON_ARCH: 64
 
     - PYTHON: C:\Python38rc1